setting yscale to log, after drawing a plot with values equal to zero, results in incorrect handling of zero values #8045
Description
mpl 1.5.3 and 2.0, py3.6
_xs = np.linspace(-50, 50, 1001); plt.semilogy(scipy.stats.norm.pdf(_xs))
results in
where zero values (due to floating point resolution limits, at the edges) get ignored, as expected, but
_xs = np.linspace(-50, 50, 1001); plt.plot(scipy.stats.norm.pdf(_xs))
plt.gcf().canvas.draw()
plt.gca().set(yscale="log")
results in the incorrect
